Coronavirus Disease 2019: Anesthesia Machine Circuit Pressure During Use as an Improvised Intensive Care Unit Ventilator.

BACKGROUND: Use of anesthesia machines as improvised intensive care unit (ICU) ventilators may occur in locations where waste anesthesia gas suction (WAGS) is unavailable. Anecdotal reports suggest as much as 18 cm H2O positive end-expiratory pressure (PEEP) being inadvertently applied under these circumstances, accompanied by inaccurate pressure readings by the anesthesia machine. We hypothesized that resistance within closed anesthesia gas scavenging systems (AGSS) disconnected from WAGS may inadvertently increase circuit pressures. METHODS: An anesthesia machine was connected to an anesthesia breathing circuit, a reference manometer, and a standard bag reservoir to simulate a lung. Ventilation was initiated as follows: volume control, tidal volume (TV) 500 mL, respiratory rate 12, ratio of inspiration to expiration times (I:E) 1:1.9, fraction of inspired oxygen (Fio2) 1.0, fresh gas flow (FGF) rate 2.0 liters per minute (LPM), and PEEP 0 cm H2O. After engaging the ventilator, PEEP and peak inspiratory pressure (PIP) were measured by the reference manometer and the anesthesia machine display simultaneously. The process was repeated using prescribed PEEP levels of 5, 10, 15, and 20 cm H2O. Measurements were repeated with the WAGS disconnected and then were performed again at FGF of 4, 6, 8, 10, and 15 LPM. This process was completed on 3 anesthesia machines: Dräger Perseus A500, Dräger Apollo, and the GE Avance CS2. Simple linear regression was used to assess differences. RESULTS: Utilizing nonparametric Bland-Altman analysis, the reference and machine manometer measurements of PIP demonstrated median differences of -0.40 cm H2O (95% limits of agreement [LOA], -1.00 to 0.55) for the Dräger Apollo, -0.40 cm H2O (95% LOA, -1.10 to 0.41) for the Dräger Perseus, and 1.70 cm H2O (95% LOA, 0.80-3.00) for the GE Avance CS2. At FGF 2 LPM and PEEP 0 cm H2O with the WAGS disconnected, the Dräger Apollo had a difference in PEEP of 0.02 cm H2O (95% confidence interval [CI], -0.04 to 0.08; P = .53); the Dräger Perseus A500, <0.0001 cm H2O (95% CI, -0.11 to 0.11; P = 1.00); and the GE Avance CS2, 8.62 cm H2O (95% CI, 8.55-8.69; P < .0001). After removing the hose connected to the AGSS and the visual indicator bag on the GE Avance CS2, the PEEP difference was 0.12 cm H2O (95% CI, 0.059-0.181; P = .0002). CONCLUSIONS: Displayed airway pressure measurements are clinically accurate in the setting of disconnected WAGS. The Dräger Perseus A500 and Apollo with open scavenging systems do not deliver inadvertent continuous positive airway pressure (CPAP) with WAGS disconnected, but the GE Avance CS2 with a closed AGSS does. This increase in airway pressure can be mitigated by the manufacturer's recommended alterations. Anesthesiologists should be aware of the potential clinically important increases in pressure that may be inadvertently delivered on some anesthesia machines, should the WAGS not be properly connected.

Social Media Use by Hand Surgery Fellowship Programs.

INTRODUCTION: Social media has emerged as a useful tool in the fellowship recruitment process. We aimed to assess the prevalence of social media use among hand surgery fellowships, to analyze social media posts according to content, and to evaluate the level of engagement generated by specific content. METHODS: We used a list of accredited hand surgery fellowships from the American Society for Surgery of the Hand Fellowship Directory to identify all hand surgery fellowship profiles on Facebook, Twitter, and Instagram. Instagram was the most commonly used platform and thus the focus of this study. Two reviewers independently assessed all Instagram posts from each program and assigned content labels. We assessed the variability in content published by each program using a Monte Carlo estimation of an exact chi-square test. We calculated the level of engagement generated by each content label using the number of likes per post per number of account followers. We analyzed the variability in engagement using a Kruskal-Wallis test. RESULTS: We identified 21 Instagram accounts from 89 fellowship programs (24%). Seventeen of 21 (81%) were created after the onset of the coronavirus disease 2019 pandemic. There was significant variability in the scope of content published by each program ( P < 0.0001) and in the level of engagement generated by each content label ( P < 0.0001). Skills, conferences, fellow, case example(s), faculty, and team dynamics generated some of the most engagement. Logistics, miscellaneous, and facilities generated the least. DISCUSSION: There is wide variability in the content produced by hand fellowship programs. Specific types of content generate more engagement from followers than others. This information may guide fellowship programs to produce the type of content potential applicants find most useful when making application and rank list decisions.

Clinical Pathways of Patients Denied Total Knee Arthroplasty Due to an Institutional BMI Cutoff.

Out of concern for the increased risk of complications with morbid obesity, institutional body mass index (BMI) cutoffs for total knee arthroplasty (TKA) have become commonplace. We sought to answer the questions: what percentage of morbidly obese patients with knee osteoarthritis who present to an arthroplasty clinic will, within 2 years, undergo TKA at (1) a BMI less than 40 kg/m2 or (2) at a BMI greater than 40 kg/m2? Of those who do not undergo surgery, (3) what percentage lose enough weight to become TKA-eligible, and (4) what percentage do not? We performed an observational study of 288 patients, of which 256 had complete follow-up. Institutional electronic medical record review and patient follow-up by telephone were conducted to determine which patients underwent surgery, and at what BMI. For those that did not undergo TKA, BMI was examined to see if the patient ever lost enough weight to become TKA eligible. Twelve of 256 patients (4.7%) underwent TKA at a BMI less than 40 kg/m2, 64 patients (25%) underwent TKA at a BMI greater than 40 kg/m2, and 7 patients (2.7%) underwent surgery at an outside hospital. The average BMI at the time of surgery was 42.3 kg/m2. Thirty-seven of 256 patients (14.4%) lost enough weight to become TKA-eligible within 2 years of the initial visit but did not undergo surgery, while 136 patients (53.1%) neither underwent TKA nor became eligible. Strict enforcement of a BMI cutoff for TKA is variable among surgeons. In the absence of weight loss protocols, 19.1% of morbidly obese patients may be expected to reach the sub-40 kg/m2 BMI milestone.

Gleason Score Evolution and the Effect on Prostate Cancer Outcomes.

OBJECTIVES: We evaluated how the changes in Gleason grading affected the long-term outcomes of a large prostatectomy cohort. METHODS: We obtained long-term follow-up (16.7 years) in 581 patients having undergone radical retropubic prostatectomy between 1985 and 1995. We excluded those with seminal vesicle and/or lymphatic involvement. We regraded the specimens according to contemporary guidelines and compared how this affected outcomes compared with their original (pre-1995) Gleason scoring. In total, 499 patients were evaluable. RESULTS: A Gleason score of 6 or less declined from 73% to 29%, and the number increased from 25% to 63% for a Gleason score of 7 and from 5% to 8% for a Gleason score of 8 to 9. As a result, for a Gleason score less than 7, biochemical failure decreased from 28% to 23%, metastatic disease 5% to 2%, and prostate cancer death from 5% to 3%. The same results were 50% to 37%, 11% to 7%, and 10% to 6% for a Gleason score of 7 and 86% to 71%, 43% to 32%, and 29% to 26% for a Gleason score more than 7, respectively. With the most recent grade grouping, for groups 1 to 5, biochemical failure occurred in 23%, 32%, 45%, 69%, and 78%, respectively. Metastatic disease occurred in 2%, 4%, 12%, 24%, and 56%, respectively. Prostate cancer-related death occurred in 2%, 4%, 9%, 21%, and 44%, respectively. CONCLUSIONS: The revised Gleason scores improved the outcomes in all risk groups. Based on Gleason score, patients with prostate cancer will appear to have better outcomes than they did before 2005, making any comparison tenable. The current grading system shows a consistent increased risk in biochemical failure, metastatic disease, and prostate cancer-related death with each successive grade.

Intraoperative navigation and preoperative templating software are associated with increased glenoid baseplate screw length and use of augmented baseplates in reverse total shoulder arthroplasty.

BACKGROUND: Preoperative templating software and intraoperative navigation have the potential to impact baseplate augmentation utilization and increase screw length for baseplate fixation in reverse total shoulder arthroplasty (rTSA). We aimed to assess their impact on the (1) baseplate screw length, (2) number of screws used, and (3) frequency of augmented baseplate use in navigated rTSA. METHODS: We compared 51 patients who underwent navigated rTSA with 63 controls who underwent conventional rTSA at a single institution. Primary outcomes included the screw length, composite screw length, number of screws used, percentage of patients in whom 2 screws in total were used, and use of augmented baseplates. RESULTS: Navigation resulted in the use of significantly longer individual screws (36.7 mm vs. 30 mm, P < .0001), greater composite screw length (84 mm vs. 76 mm, P = .048), and fewer screws (2.5 ± 0.7 vs. 2.8 ± 1, P = .047), as well as an increased frequency of using 2 screws in total (35 of 51 patients [68.6%] vs. 32 of 63 controls [50.8%], P = .047). Preoperative templating resulted in more frequent augmented baseplate utilization (76.5% vs. 19.1%, P < .0001). CONCLUSION: The difference in the screw length, number of screws used, and augmented baseplate use demonstrates the evolving role that computer navigation and preoperative templating play in surgical planning and the intraoperative technique for rTSA.

Predictive value of lateral soft tissue thickness for complications after total hip arthroplasty with a lateral incision.

The purpose of this study was to determine the relationship between soft tissue thickness lateral to the greater trochanter, as measured on anteroposterior pelvis radiograph, and postoperative complications following primary total hip arthroplasty. A retrospective review of 1110 consecutive patients treated at a single institution from 2003 to 2011 was conducted. Postoperative complications were divided into surgical site infections, deep wound infections, noninfectious surgical complications, need for revision surgery, and medical complications. Lateral soft tissue thickness (LSTT) was measured as the horizontal distance from the most lateral point on the greater trochanter to the skin edge obtained from anteroposterior hip radiographs. Among the 1110 study patients, 19.19% had a postoperative complication, with a deep infection rate of 3.42%. Of the previously identified risk factors, increased LSTT and body mass index were both associated with surgical site infection and deep infection, and LSTT was associated with revision surgery. An LSTT value of >5 cm was predictive of surgical site infection, deep infection, and revision surgery. This easily obtainable radiographic measurement, along with clinical examination near the operative site, might prove helpful in making preoperative risk assessments.

Respiratory failure as presentation of achalasia of the oesophagus.

A 68-year-old woman with a history of hiatus hernia developed aspiration pneumonia after operation for fractured neck of femur. After 8 days, acute respiratory failure was caused by massive retention of air and food in the oesophagus. This was relieved by aspiration, and treated by balloon dilation of the gastric cardia.

Leukotriene B4 as a marker of cerebral dysfunction.

It has been postulated that leukotriene B4 is involved in the pathogenesis of postischaemic cerebral oedema. We set out to determine if a relationship exists between jugular bulb leukotriene B4 and other indicators of cerebral ischaemia. No association could be demonstrated for either intracranial pressure, jugular bulb blood oxygen saturation or lactate oxygen index. Our results provide insufficient evidence to suggest that measurement of leukotriene B4 has any place in the management of head-injured patients.

Pulmonary consequences of carbon dioxide insufflation for laparoscopic cholecystectomies.

Twenty patients having laparoscopic cholecystectomies were studied for changes in thoracic and lung compliance at 5, 10 and 15 mmHg of intra-abdominal pressure. Fifteen mmHg of intra-abdominal pressure decreased the thoracic and the lung static compliance by 49 and 39% respectively. This was unaffected by the degree of head elevation. During the procedure the end-tidal carbon dioxide increased by a mean of 1.6 kPa at 1 h and 2.0 kPa at 2 h. This did not appear to be related to either the mean intra-abdominal pressure or the total volume of carbon dioxide insufflated. The physiological changes and implications for anaesthetic practice are considered.

Resistance and additional inspiratory work imposed by the laryngeal mask airway. A comparison with tracheal tubes.

Laryngeal mask airways and tracheal tubes were studied to determine both their resistance to constant gas flows and additional inspiratory work during simulated inspiration. Laryngeal mask airways imposed less resistance and required lower additional inspiratory work compared with the corresponding sized tracheal tubes. If inspiratory loading during anaesthesia is an important consideration, then the laryngeal mask airway may be preferable to a tracheal tube.